I like the cap/seal idea to keep the crack from refilling with trash/feces.
Maybe some 2' sections of 6" or so diameter logs could be used to make the cap/seal instead of cement or foam. Trim to fit with a saw and hammer into place! They will rot and get smaller over years, but then hammer deeper to retighten; add a new layer on top eventually.
Hey guys I am a foam insulation contractor and know that the foam will work, but here are some pro's and cons.
1. You have to use a closed cell foam 2 pound minimum.
2. You can paint the foam grey and blend it no problem.
3. You can chip away at any foam and rodents will chew that up and make homes in it.
4. The closed cell foam would have to be taken up in 4 propane size tanks and sprayed into the crack. Polyol Resin and Isocyanate. When combined make Cyanide vapors. We wear full face respirators and fresh air when we foam.
5 Closed cell foam would have to be done in temps lower than 75 degrees.
The chemical makeup of closed cell causes it to froth and foam in the canister over 80 degrees and it should not be shaken up at all or you will have to wait a day for it to settle down.
6 I'm sure the NPS would crap there pants if you put foam in the crack as it is against about everything they say the park is about. ( Natural)
7. I would just jam it with logs and and natural debris that would stay in place and not wash out of there.
8. Camp 6 is a water course in spring or after heavy rain.
9. Expensive to foam.
10 dont even think Great Stuff will work. It will hold water if emerged for long periods of time.
In physical terms, anything that might be put into the crack behind the Camp VI ledge, to block people from throwing garbage and crapping in it, will be a challenge. That is, to prevent climbers from putting things in the crack, without altering the character of the climb or creating problems.
Something solid (concrete, foam): Fills crack, maybe too permanent (trial seems advisable), may get in way, contrary to NPS requirements.
Something semi-solid (wood): Impermanent/requires maintenance, maybe contrary to NPS requirements, may disintegrate and fall out on those below.
Non-solid barrier (mesh): Impermanent, doesn't really stop people from stuffing things through and around.
Something soft (gravel, sand): Well, my cat would show how to use it for a litter box.
Signage, and perhaps a concerted information campaign, may help. Bearing in mind that many climbers come from around the world to climb the Nose, but are from places and cultures with different values and behaviours in terms of waste.
Another option would be a solar-powered camera off to the side, focused on the Camp VI area, maybe including a night-vision feature. ("Big Sibling is watching you...")
Or perhaps a poop chute running the length of the Nose, into which people could conveniently load their waste. Probably some maintenance challenges, but gravity would definitely do its bit.
People nearly come to cyber blows when it comes to adding a bolt or defacing the rock in ANY way and people are seriously considering capping a crap hole?
On El Cap no less??
I guess it is the Friday before a holiday weekend (?) traffic is probably light on the taco today...